Radio frequency module and communication device

Abstract

A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying element; a second amplifying element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying element, another end of the primary coil is connected to an output terminal of the second amplifying element, an end of the secondary coil is connected to an output terminal of the power amplifier, the first amplifying element and the second amplifying element are disposed on the first principal surface, and the first circuit component is disposed on the second principal surface.

The invention claimed is: 
     
       1. A radio frequency module, comprising:
 a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; 
 a low noise amplifier that is disposed on the second principal surface and configured to amplify a reception signal; and 
 a power amplifier configured to amplify a transmission signal, the power amplifier including
 a first amplifying element disposed on the first principal surface; 
 a second amplifying element disposed on the first principal surface; 
 a first transformer that includes a first coil and a second coil; and 
 a second transformer that includes a third coil and a fourth coil, wherein 
 
 an end of the second coil is connected to an input terminal of the first amplifying element, 
 another end of the second coil is connected to an input terminal of the second amplifying element, 
 an end of the third coil is connected to an output terminal of the first amplifying element, 
 another end of the third coil is connected to an output terminal of the second amplifying element, and 
 an end of the fourth coil is connected to an output terminal of the power amplifier. 
 
     
     
       2. The radio frequency module of  claim 1 , wherein
 the first amplifying element, the second amplifying element, and the first transformer are included in a single semiconductor integrated circuit (IC), and 
 the single semiconductor IC is disposed on the first principal surface. 
 
     
     
       3. The radio frequency module of  claim 1 , wherein
 the power amplifier further includes a third amplifying element connected to the first transformer and disposed upstream on a signal path from the first amplifying element and the second amplifying element. 
 
     
     
       4. The radio frequency module of  claim 3 , wherein
 the first transformer is disposed on the second principal surface, and 
 in a plan view of the module board, a footprint of the third amplifying element at least partially overlaps a footprint of the first transformer. 
 
     
     
       5. The radio frequency module of  claim 3 , wherein
 the first transformer is disposed between the first principal surface and the second principal surface, and 
 in a plan view of the module board, a footprint of the third amplifying element at least partially overlaps a footprint of the first transformer. 
 
     
     
       6. The radio frequency module of  claim 1 , further comprising:
 a plurality of external-connection terminals disposed on the second principal surface; and 
 a heat-dissipating via conductor that is connected to a ground electrode of the first amplifying element and the second amplifying element and extends from the first principal surface to the second principal surface. 
 
     
     
       7. The radio frequency module of  claim 6 , wherein
 the heat-dissipating via conductor is connected, on the second principal surface, to a first external-connection terminal having a ground potential out of the plurality of external-connection terminals. 
 
     
     
       8. The radio frequency module of  claim 7 , wherein
 in a plan view of the module board, the first external-connection terminal is disposed between the first transformer and the low noise amplifier. 
 
     
     
       9. The radio frequency module of  claim 1 , wherein
 the second transformer is disposed on the first principal surface. 
 
     
     
       10. The radio frequency module of  claim 9 , wherein
 in a plan view of the module board, no circuit component is disposed in a region of the second principal surface that overlaps the second transformer. 
 
     
     
       11. The radio frequency module of  claim 9 , wherein
 in a plan view of the module board, no circuit component is disposed in a region of the first principal surface that overlaps the second transformer. 
 
     
     
       12. The radio frequency module of  claim 1 , wherein
 the second transformer is disposed between the first principal surface and the second principal surface, and 
 in a plan view of the module board, no circuit component is disposed in regions of the first principal surface and the second principal surface that overlap the second transformer. 
 
     
     
       13. The radio frequency module of  claim 1 , wherein
 the second transformer is disposed between the first principal surface and the second principal surface and closer to one of the first principal surface and the second principal surface than another of the first principal surface and the second principal surface. 
 
     
     
       14. The radio frequency module of  claim 13 , wherein
 in a plan view of the module board, no circuit component is disposed in a region of the one of the first principal surface and the second principal surface that overlaps the second transformer. 
 
     
     
       15. The radio frequency module of  claim 14 , wherein
 in the plan view of the module board, a circuit component is disposed in a region of the another of the first principal surface and the second principal surface that overlaps the second transformer. 
 
     
     
       16. The radio frequency module of  claim 1 , wherein
 in the plan view of the module board, an external-connection terminal having a ground potential is disposed between the second transformer and the low noise amplifier. 
 
     
     
       17. The radio frequency module of  claim 1 , further comprising:
 a control circuit disposed on the first principal surface and configured to control the power amplifier. 
 
     
     
       18. A communication device, comprising:
 an antenna; 
 a radio frequency (RF) signal processing circuit configured to process radio frequency signals transmitted and received by the antenna; and 
 a radio frequency module configured to transfer the radio frequency signals between the antenna and the RF signal processing circuit, 
 the radio frequency module including
 a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; 
 a low noise amplifier that is disposed on the second principal surface and configured to amplify a reception signal; and 
 a power amplifier including
 a first amplifying element disposed on the first principal surface; 
 a second amplifying element; and 
 a transformer including a primary coil and a secondary coil, wherein 
 
 a first end of the primary coil is connected to an output terminal of the first amplifying element, 
 a second end of the primary coil is connected to an output terminal of the second amplifying element, and 
 a first end of the secondary coil is connected to an output terminal of the power amplifier. 
 
 
     
     
       19. A radio frequency module, comprising:
 a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; 
 a low noise amplifier that is disposed on the second principal surface and configured to amplify a reception signal; and 
 a power amplifier including
 a first amplifying element disposed on the first principal surface; 
 a second amplifying element; and 
 a transformer including a primary coil and a secondary coil, wherein 
 
 a first end of the primary coil is connected to an output terminal of the first amplifying element, 
 a second end of the primary coil is connected to an output terminal of the second amplifying element, and 
 a first end of the secondary coil is connected to an output terminal of the power amplifier.